1. FIELD OF THE INVENTION
The present invention relates broadly to a novel supporting structure which is readily adaptable for use as a pole lamp supporting means, and more particularly to a nonrotatable telescoping supporting structure for use in constructing electric lighting lamps wherein the electric wires are disposed within the telescoping members and, relative rotation between the members is prevented thereby significantly reducing the changes of damaging the electrical wires running therethrough. The present invention therefore provides for an improved supporting means which fully complies with generally accepted safety codes.
2. DESCRIPTION OF THE PRIOR ART
Various attempts have been made in the past to produce a nonrotatable telescoping supporting means for use in lamps which, usually included the inner member having an elongated stationary guide means. The use of elaborate and complicated mechanisms to prevent rotation of telescoping members have been utilized in the past, but such means include the stationary guiding structure located on additional components which do not form part of the telescoping members themselves.
There exists prior art U.S. patents which disclose nonrotatable telescoping supporting structures. However, none of the prior art patents teaches or suggests in any manner, either singly or in combination, the structure disclosed herein.
The prior art U.S. patents Nos. known to Applicant are as follows:
Cole: 3,012,801 PA1 Cole et al: 2,902,592 PA1 Wolar: 2,748,261 PA1 Jarrett et al: 2,553,094 PA1 Starck: 2,409,075 PA1 Doane: 2,994,886
Jarret et al discloses a screw 51 having a rounded terminal positioned in the upright support 25 and the terminal projects entirely through and into the slot 52 in the adjustable post 29 to provide upward and downward limits of movement of the post 29.
Doane shows the use of a cross bar located within the telescoping lamp parts, which bar extends completely through the inner tube to prevent rotation and limit travel vertically.
Wolar discloses lugs which are apt to cooperate with T-shaped slots formed in the inner member to adjust the height of a lighting fixture supporting means. The elaborate configuration of the slots is adapted to facilitate small increments of vertical adjustments.
Starck and Cole et al show the use of a longitudinal groove formed in the inner member which is adapted to engage elongated ridges therein.
Cole shows the use of internal buttons 23 and a longitudinal indentation 34 to limit rotation to a predetermined angle.